Presuming that this is not a wind-up, if he is monitoring your computer, he already knows that you know.
Have your computer cleaned by a professional. There are in-home services that provide this.
Change the locks on your doors and have a security system installed.
Contact a lawyer, or if you really feel threatened, call the police, NOW !
Not necessarily in that order.
Worrying about someone's career when your safety is at stake is highly questionable judgment.